Banking on Local Greens
It’s the frustration of every gardener in the Inland Northwest and other northern parts of the country: You plant lettuce as soon as you can work the soil in the spring, but the temperature takes a dive, and instead of providing an early harvest, your seeds rot in the ground.
Although lettuce is a cool-season crop, current varieties won’t germinate if it gets too cold. According to Gardening in the Inland Northwest by Tonie Fitzgerald of WSU Extension’s Master Gardener program, lettuce will germinate at soil temperatures as low as 35 degrees Fahrenheit, but the optimal soil temperature is a much higher 75 degrees. If the germination temperature could be pushed downward, both gardeners and commercial growers could plant early with confidence
But how to train lettuce seeds to germinate at lower temperatures? Carol Miles, a vegetable horticulture specialist at the WSU Mount Vernon Northwestern Washington Research and Extension Center (NWREC), suspects there are lettuce lines unknown to commercial breeders that can germinate early, and that these traits can be transferred to commercial lettuce varieties for the thrill of anyone who has spaded a frosty garden in April.
To obtain sources of lettuce for testing, Miles decided against traveling to Asia Minor, Iran, and Turkistan where lettuce originates, and scouring mountain drainages and rural gardens for lettuces new to the West. Instead, she took advantage of the 295 different types of lettuce seeds housed at the USDA Western Regional Plant Introduction Station (WRPIS) in Pullman. The station is one of four regional seed repositories in the National Plant Germplasm system.
Miles and her graduate student Charlene Grahn established a climate-controlled growth chamber where they planted lettuce seeds from the seed bank and identified those that germinated at the coldest temperatures. They have just harvested the first season’s crop, and are compiling the results. When the final numbers are in, commercial breeders can choose the most appealing lettuce lines and incorporate the cold-tolerant trait into varieties for commercial growers and gardeners.
“Almost all major crops in the United States–wheat, rice, and soy, for instance–were brought here from somewhere else,” explained Jinguo Hu, research leader of the USDA WRPIS. Imported crops tend to lack genetic diversity, which leaves them vulnerable to challenges such as harmful insects and diseases. “The National Plant Germplasm system was started in 1946 as a way to preserve plant diversity and breeding opportunities for future generations.” The Pullman center has 93,000 accessions, or deposits of seeds collected from a specific place at a specific time. Like all of the regional centers, the WRPIS specializes in specific types of plants. In addition to 2,000 accessions of lettuce, Pullman has over 17,000 accessions of beans, 21,000 accessions of turf and forage grass, 9,000 accessions of forage legumes, and 6,100 accessions of peas.
Historical Success and Current Potential
Hu knows the potential of this collection for lettuce breeding, because he has seen success with other plants. “Early chickpea cultivation was limited in the United States due to problems with Ascochyta blight,” said Hu. But once a specimen was found to be resistant to the causal fungus Ascochyta rabiei, breeders incorporated the resistant gene into the crop, and chickpeas became widely grown again in the West. Peas are also among the success stories, having similarly gained resistance to powdery mildew through selective breeding from the collection.
Miles, serving as the WSU representative to the Western Regional Repository, has a great deal of respect for the value of the repository system. In addition to lettuce research, she and grad student Jesse Wimer are using the collection to find cucurbits (plants in the gourd family) that can be used as disease-resistant rootstock for watermelon grafts. She is also helping Hu find fava bean strains that are cold-tolerant.
The largest impact is likely to come from the lettuce research, however. “Lettuce is the number one vegetable consumed in the United States,” said Miles. “Most of the past seed screening has been to find strains that resist high temperatures. If breeders can develop varieties that grow better at low temperatures, there will be great new opportunities for local food systems.” Instead of eating lettuce shipped thousands of miles from the Sun Belt, northerners might be munching more greens purchased at their local farmers market or harvested in their own backyards.
For more information about the WRPIS, see http://1.usa.gov/1deYiyB. To learn more about vegetable research at WSU Mt. Vernon, see http://bit.ly/wsumtv. To purchase Gardening in the Inland Northwest, go to http://bit.ly/15fG116.
Technology Takes Manure beyond Waste Management
WSU scientists are proving that dairy manure management does not have to be considered an environmental liability. New technologies that complement anaerobic digestion, a biological process of breaking down organic waste material, were showcased at the WSU Anaerobic Digestion Field Day in Lynden, Wash., in July.
Manure management has long been a challenge for dairy operations because it can contribute to air and water quality problems including greenhouse gas emissions and excess nutrients (nitrogen and phosphorus) in soil and water. However, over the last decade, advances in anaerobic digestion (AD) systems have evolved not only to manage waste, but to help dairies address pressing environmental problems and generate revenue at the same time.
At Vanderhaak and Edaleen dairies in Lynden, Wash., over 115 field day participants could see, but not smell, anaerobic digesters at work. Anaerobic digesters greatly diminish manure odors. They also decrease pathogens in dairy waste and capture methane, thereby reducing greenhouse gas emissions and producing biogas which can be used to produce electricity to power the AD system or to send to the grid.
To broaden the circle of organic waste management, the digesters at Vanderhaak and Edaleen dairies co-digest food waste like processed raspberry culls and waste generated from nearby Maberry Farm.
New Green Fuel Technology
A new add-on technology, called biogas scrubbing, allows the biogas produced through anaerobic digestion to be refined into renewable natural gas, or RNG, which is clean and ready to use as vehicle fuel. Renewable natural gas can directly replace compressed natural gas or liquid natural gas for use in trucks and cars. According to Dan Evans of the renewable energy company Promus Energy LLC, “RNG can be delivered to trucking fleets at half the price of diesel and may be the greenest of all fuels.” Evans explained that RNG is “green” not only because it is derived from a process that reduces greenhouse gas emissions but because it comes from a renewable source.
“The system pays for itself right out of the chute because we’re signing up buyers now. We’re selling renewable natural gas to compressed natural gas users who are willing to change the type of fuel they use,” Evans said. Existing demand and environmental credit and incentive programs are expected to make this manure-derived fuel product cost- effective and profitable.
Recovering Nutrients for Cash and Compliance
Another new technology that can be integrated with anaerobic digesters is the recovery of excess nutrients which are a problem for the environment and a concern for dairies which face increasing regulations.
Nutrient recovery systems, such as the AIR-TRAP system developed by WSU scientist Craig Frear and industrial partners DVO Incorporated and Andgar Corporation, promise to turn excess nitrogen and phosphorus into marketable fertilizers and soil amendments before they ever become a problem in soil and water.
The list of recovered nutrient products that are beginning to emerge on the market includes a fiber material that can be used to replace peat moss, a pathogen-free ammonium sulfate fertilizer, and a phosphorus-rich soil amendment. These products can be more easily transported and more precisely applied to fields than manure and have greatly reduced potential for pathogens. While products are entering the market now, continued development of markets and improvements in product quality are still required.
Besides the potential for value-added products, full nutrient recovery offers dairies a way to comply with regulations at little or no cost, Frear said.
“We think this will be a cost-neutral system,” Frear said. “In the future, when markets mature, dairies may make money from the products. But they are also interested in nutrient recovery because of the potential in the near future to be regulated for ammonia and nitrogen-derived outputs.” The AIR-TRAP system removes excess nitrogen from manure, reducing the potential for soil microbes to convert the nitrogen into nitrates that could end up in groundwater.
Nutrient recovery is quickly gaining attention among dairy operators, environmental regulatory agencies, and entrepreneurs.
The Bottom Line
The WSU team lead by Frear recognizes that keeping the bottom line in sight is critical in developing technologies that dairies and other livestock operations will adopt. According to Chad Kruger, director of the WSU Center for Sustaining Agriculture and Natural Resources (CSANR), the not-insignificant cost of the anaerobic digester itself is a small portion of the capital and operating costs of the whole anaerobic digestion system.
“What’s more important to consider is the profitability of the project scenario that you put together,” Kruger said. “Adding nutrient recovery to the system adds capital and operating costs, but for the most part it is cost-neutral if scaled appropriately and if there is a market for the resulting products.” Several reports published by CSANR spell out the details of the economic feasibility of anaerobic digestion systems and newer add-on technologies, and are available on their website.
After lunch, as field day participants enjoyed ice cream donated by Edaleen Dairy and berries from Maberry Farm, perhaps it tasted a bit sweeter knowing that, thanks to new technologies developed by WSU scientists and their industry partners, manure management doesn’t have to be the environmental burden it once was considered.
The US Environmental Protection Agency estimates that currently there are 167 anaerobic digester systems operating at commercial dairies in the United States and eight in Washington. The potential to help livestock operations comply with environmental regulations while turning a profit and reducing greenhouse gas emissions, suggests that more anaerobic digestion systems are likely in the cards for the state and the nation.
Organic Farm Field Day Focuses on Quinoa, New Research
The 2013 Organic Farm Field Day brought growers, students, researchers, and organic gourmands out to the two WSU
organic farms on Thursday, July 25.
Assistant Research Professor Kevin Murphy and graduate students from the WSU Department of Crop and Soil Sciences, reviewed the progress of their research field trials on quinoa and other alternative crops at the Tukey Horticultural Orchard. Quinoa was of particular interest as the Pacific Northwest and International Quinoa Symposium approaches August 12-14 and as researchers are looking at how to best grow the crop in the Pacific Northwest.
A tour of the new Eggert Family Organic Farm was given following a tour of the Tukey Organic Farm. Dr. Lynne Carpenter-Boggs gave an update on the farm’s progress and led a tour of the newly planted orchard. Todd Beyreuther, director of the WSU Integrated Design Lab, discussed the latest designs for structures on the farm and current work in progress, including a community gathering area and the student-designed Harvest Pavilion, construction of which will begin this summer.